Frame for fluid machines

ABSTRACT

Herein described is a frame for a fluid machine of the reciprocating type. The frame bears one or more cylinders moving inside each of which, with a reciprocating movement, is a piston operated by a crankshaft. The frame is made up of one or more modules of the same size and shape, within each one of the modules being provided a single chamber adapted to accommodate the crank mechanisms of each single cylinder. Each module is further provided with a pair of opposite side walls and with one or more fixing means which allow rigid coupling to each other, adjacently arranging their respective side walls, of two or more of the identical modules for providing a frame for fluid machines provided with two or more cylinders.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/451,447, filed on Nov. 30, 2009, and entitled “Frame for FluidMachines,” which is a §371 application of International ApplicationSerial No. PCT/IB2008/001205, filed on May 9, 2008 and entitled “Framefor Fluid Machines,” which claims priority to Italian Patent ApplicationSerial No. MI 2007 A 001000, filed on May 17, 2007. The content of theseapplications is incorporated by reference herein in its entirety.

The present invention regards the fluid machines and, more inparticular, it refers to a frame for reciprocating compressors.

As known, a compressor is a special kind of machine capable ofexploiting the task performed by an engine to increase the pressure of acompressible fluid (gas or vapour). In reciprocating compressors, thecompression of the fluid is performed by one or more moving pistons withreciprocating movement within a respective cylinder. The fluid to becompressed is suctioned into the cylinder by a suctioning pipe, whilethe compressed one is ejected from the cylinder towards a dischargepipe. Usually, the piston or pistons of a reciprocating compressor areoperated by electric motors or by internal combustion engines through acrankshaft for transmitting drive and a traditional connecting rod/crankmechanism.

The industrial reciprocating compressors are usually provided with anexternal casing, referred to as frame, whose purpose is to accommodatethe connecting rod/crank mechanism and bear the cylinder or cylinders,countering the reciprocating forces generated upon compression of thefluid.

As of date, the frames for reciprocating compressors, generally made bymelting metal and/or machining by means of tool machines, are made up ofa single body capable of resisting against the stresses generated duringthe compression cycle and subsequent to the rotational movement of thedriving shaft for transmitting drive to the pistons. Thus each singlecompressor must be provided with a specific frame depending on thenumber of cylinders, usually arranged vertically and in a linear manner,with which it is provided. Consequently, it is necessary to design andmanufacture each frame separately, substantially increasing both thecosts and the production time.

Thus, the objective of the present invention is to provide a frame forfluid machines, in particular but not exclusively reciprocatingcompressors, capable of being used indistinctively both onsingle-cylinder machines and on two or multi-cylinder machines, withoutrequiring different dies to obtain the specific frames depending on thenumber of cylinders of the machine.

Another objective of the invention is to provide a frame for fluidmachines capable of facilitating and quickening the assembly of themachine with respect to known art.

Still, another objective of the invention is to provide a frame for afluid machine capable of allowing reduction of costs and production timeas well as storage in the warehouse.

These objectives according to the present invention are attained bymanufacturing a frame for fluid machines, in particular but notexclusively reciprocating compressors, as described in claim 1.

Further characteristics of the invention are outlined by the subsequentclaims.

Characteristics and advantages of a frame for fluid machines, inparticular but not exclusively reciprocating compressors, according tothe present invention shall be clearer from the following exemplifyingand non-limiting description with reference to the schematic drawingsattached wherein:

FIG. 1A is a top plan view of a frame for fluid machines according tothe present invention, applied to a single-cylinder reciprocatingcompressor;

FIG. 1B is a sectional view obtained along line A-A of FIG. 1A;

FIG. 2A is a top plan view of a frame for fluid machines according tothe present invention, applied to a two-cylinder reciprocatingcompressor;

FIG. 2B is a sectional view obtained along line A-A of FIG. 2A;

FIG. 3A is a top plan view of a frame for fluid machines according tothe present invention, applied to a four-cylinder reciprocatingcompressor;

FIG. 3B is a sectional view obtained along line A-A of FIG. 3A;

FIG. 4 is a side elevation view of a frame for fluid machines accordingto the present invention; and

FIG. 5 is a side elevation view of a frame for fluid machines accordingto the present invention, on which one or more cylinders of fluidmachines of a reciprocating type are vertically mounted.

Referring to the figures, schematically shown is a frame for fluidmachines, indicated in its entirety with reference number 10 and appliedas an example to a vertical reciprocating compressor for compressiblefluids, which can be used in any gas compression station or system.

The frame 10 is provided to bear one or more cylinders 12, moving insideeach of which, with a reciprocating movement, is a piston (not shown);operated by a crankshaft 14. The fluid to be compressed is introducedinto each cylinder 12 through one of more suctioning pipes 18, while thecompressed fluid is ejected from the cylinder 12 itself towards one ormore discharge pipes 18′.

According to the invention, the frame 10 is made up of one or moremodules 20 of the same shape and size, within each module 20 beingprovided a single chamber 16 adapted to accommodate the crank mechanismsof each single cylinder 12. In addition, each module 20 is provided witha pair of substantially flat opposite side walls 22 and 24 and with oneor more fixing means 26 which allow rigid coupling to each other,adjacently arranging their respective side walls, of two or moreidentical modules 20 to provide a frame 10 for compressors provided withtwo or more cylinders 12, as shown for example in FIGS. 2A, 2B, 3A and3B.

In the embodiments illustrated the fixing means 26, preferably made upof bolts of the known type, are inserted into suitable holes 26′ made oneach side wall 22, 24 of each module 20, thus allowing to arrange themodules 20 themselves adjacent to each other in such a manner to provideframes 10 for reciprocating compressors provided with two cylinders(FIGS. 2A and 2B), three cylinders, four cylinders (FIGS. 3A and 3B) andmore, without any restriction regarding the number of cylinders.

In such manner, it is possible to adapt the frame 10 according to theinvention in a flexible manner to various types of reciprocatingcompressors, both with one or more cylinders, without requiringdifferent frames depending of the number of cylinders of the machine.

Each of the identical modules 20 making up the frame 10 according to theinvention can be made according to methods known to the industry, forexample through melting metal (cast iron) or through machining by meansof tool machines. In order to facilitate the coupling of the modules 20in case of multi-cylinder compressors, made on one of the side walls 22of each single module 20 can be at least one shaped portion 28 which isinserted in a shape-coupling manner into a respective shaped portion 30provided on the other side wall 24 of the adjacent module 20. Due to theminimum clearance between the shaped portions 28 and 30 and the presenceof one or more centering pins 32 fitted onto the side walls 22 and 24,as well as the presence of the fixing bolts 26 and the friction forcesgenerated between the adjacent walls 22 and 24 of the adjacent modules20, the modules 20 of the frame 10 are capable of efficiently resisting,when coupled to each other, against the forces generated during theoperation cycle of the compressor just like the case single-block framesaccording to the known art.

Furthermore, each module 20 is provided, on each of its side walls 22and 24, with a circular hole 34 which allows the passage of thecrankshaft 14 and possibly one or more rotating countershafts, ifpresent on the compressor. In order to prevent excessive flexure stressof the crankshaft 14 during the operation of the machine there can beprovided one or more support plates 36 which can be inserted into theholes 34. The support plates 36 of the crankshaft 14 are fixed into theside walls 22 and 24 of each module 20 by means of a plurality of bolts38. In addition, when the modules 20 are coupled to each other toprovide a frame 10 adapted to support more cylinders 12 and,consequently, when the holes 34 of the modules 20 adjacent to each otherare connected to each other to allow the passage of the crankshaft 14(FIGS. 2B and 3B), support bearings 40, inserted into the holes 34, canbe provided to support the crankshaft 14 itself.

It has thus been observed that the frame for fluid machines, inparticular but not exclusively reciprocating compressors, according tothe present invention attains the objectives outlined previously. Indetail, the use of a single metal module made from a single die allowsto provide, in an easy and quick manner, modular frames for machineswith any number of cylinders. This occurs simply by assembling a numberof modules corresponding to the number of cylinders of the machine toeach other.

The frame for fluid machines, in particular but not exclusivelyreciprocating compressors, of the present invention thus conceived is inany case susceptible to various modifications and variants, all fallingwithin the same invention concept; furthermore, all the details can bereplaced by technically equivalent elements. In practice, the materialsused, alongside their dimensions and shapes, may vary depending on thetechnical requirements.

Therefore, the scope of protection of the invention is defined by theattached claims.

What is claimed is:
 1. A reciprocating compressor, comprising: a framecomprising two modules of the same size and shape, each of the twomodules having a pair of sidewalls and a single chamber forming acylinder; a piston disposed in the cylinder; a crankshaft extendingthrough the pair of sidewalls of the two modules; and a fastenerextending through the pair of sidewalls of the two modules to rigidlycouple the two modules together to position one of the pair of sidewallson each of two modules adjacent to one another.
 2. The reciprocatingcompressor of claim 1, further comprising centering pins disposed in thesidewall of the two modules that are adjacent to one another.
 3. Thereciprocating compressor of claim 1, wherein the pair of sidewalls oftwo modules include a circular hole to receive the crankshaft.
 4. Thereciprocating compressor of claim 3, further comprising a support platedisposed in the circular hole of one of the pair of sidewalls of the twomodules, wherein the support plate is adapted to prevent excessiveflexure stress of the crankshaft during operation of said reciprocatingcompressor.
 5. The reciprocating compressor of claim 4, furthercomprising a plurality of bolts that affix the support plate to thesidewall of the two modules.
 6. The reciprocating compressor of claim 5,wherein the plurality of bolts are disposed circumferentially about thecircular hole.
 7. The reciprocating compressor of claim 1, furthercomprising one or more support bearings disposed about the crankshaft.8. The reciprocating compressor of claim 1, further comprising one ormore suctioning pipes coupled with the cylinder.
 9. The reciprocatingcompressor of claim 8, further comprising one or more discharge pipescoupled with the cylinder.
 10. The reciprocating compressor of claim 1,wherein the sidewalls have a shaped portion that insert in ashape-coupling manner on the one of the pair of sidewalls on each of twomodules adjacent to one another.
 11. A fluid machine for compressingfluids, said fluid machine comprising: a first module comprising a firstsidewall and forming a first chamber with a first piston disposedtherein; a second module coupled to the first module and having the samesize and shape, the second module comprising a second sidewall that isadjacent to the first sidewall, the second module forming a secondchamber with a second piston disposed therein; a crankshaft extendingthrough the first module and the second module; and a fastener extendingthrough the first sidewall and the second sidewall to rigidly couple thefirst module to the second module.
 12. The reciprocating compressor ofclaim 11, wherein the first sidewall and the second sidewall have acircular hole to receive the crankshaft.
 13. The reciprocatingcompressor of claim 12, further comprising a support plate disposed inthe circular hole of the first sidewall and the second sidewall, whereinthe support plate is adapted to prevent excessive flexure stress of thecrankshaft during rotation of the crankshaft.
 14. The reciprocatingcompressor of claim 13, further comprising a plurality of bolts thataffix the support plate to the first sidewall of the two modules
 15. Thefluid machine of claim 11, further comprising one or more pipes coupledwith at least one of the first chamber and the second chamber.
 16. Thefluid machine of claim 11, further comprising a shaped portion thatinsert in a shape-coupling manner on the second sidewall that isadjacent to the first sidewall.
 17. A compressor, comprising, a framecomprising a plurality of modules of the same size and shape, each ofthe plurality of modules having a sidewall and a chamber, wherein theplurality of modules are rigidly affixed to one another by fastenersextending through the plurality of modules; a piston disposed in thechamber of each of the plurality of modules; and a crankshaft extendingthrough the plurality of modules.
 18. The compressor of claim 17,further comprising bearings disposed about the crankshaft, wherein thebearings reside in the sidewall.
 19. The compressor of claim 17, furthercomprising a support plate disposed in a circular hole of the sidewall,wherein the support plate is adapted to prevent excessive flexure stressof the crankshaft during rotation of the crankshaft
 20. The compressorof claim 17, wherein the sidewall a shaped portion disposed on thesidewall that insert on adjacent ones of the plurality of modules in ashape-coupling manner.